The present invention generally relates to an automobile assembly line and, more particularly, to a hanger conveyance for transporting automobile door assemblies from a loading site to an unloading site through an outfitting workshop separately from, but in coordinated relation with the main flow of a production process.
An in-line automobile assembly plant includes a plurality of work stations arranged in line so that workers are assigned intensified workshops based on the division of labor for the purpose of minimizing the time costs of tooling up and also accomplishing labor-saving efforts. In this in-line assembly plant, and at each work station, a worker is generally assigned a somewhat exclusive tooling job allocated to such work station so that the worker will not be disturbed or annoyed about some other job unfamiliar to such worker or in which such worker is not skilled.
Japanese Laid-open Patent Publication No. 53-8884, published Jan. 25, 1978, discloses a door transport system comprising a pair of separate door conveyance lines arranged on respective sides of a trunk overhead conveyor for the transport of an automobile body structure through, for example, an interior fitting station at which the interior make-up is performed, which conveyance lines are for the transport of left-hand and right-hand automobile door assemblies, respectively.
Each of the conveyance lines includes an overhead conveyor extending, with respect to the direction of transport of the associated door assembly, from a door loading site, at which the associated door assembly removed from an automobile body structure is loaded on a hanger suspended from the respective overhead conveyor, back to the same loading site through a door fitting station, at which door outfittings are installed on the associated door assembly, and then through a door unloading site at which the associated door assembly with the outfittings on is unloaded from the hanger and onto a carriage in readiness for the fitting to the same automobile body structure.
According to the prior art transport system disclosed in the above mentioned publication, since the overhead conveyor is employed for each of the left-hand and right-hand automobile door assemblies, not only is a relatively increased number of the hangers required as a whole, but also the total length of the conveyance lines is relatively great, requiring a relatively large space to be occupied thereby.